Tool head



Jan. 15, 1963 w. J. ONEILLY 3,073,027

TOOL HEAD Filed April 4. 1960 3 Sheets-Sheet 1 ayagwy w A 77' ORA/E Y 3,073,027 TOOL HEAD William Jack QNeilly, Weybridge, England, assignor to The Universal Flaymaster Equipment Company Llmited, Weybridge, England, a British company Filed Apr. 4, 1960, Ser. No. 19,901 4 (Ilaims. (Cl. 30-216) This invention is concerned with mechanical cutting or llaying tools (hereinafter simply called cutting tools) of the kind comprising a cutting head, two oppositely oscillating blades in the head and means in the handle for operating the blades.

Known tools are quite satisfactory up to a point but there are difficulties, for example, it is not easy to .arrange the correct pressure between the blades which move relatively to one another. Some constructions use an annular coiled or crinkled strip spring to press one blade against the other, and this is effective for a time but for several reasons is not a complete answer. For example, the spring tends to act as a brake on the cutters causing overheating of sliding or oscillating cutters,

wastage of energy without eliminating the defect they were intended to cure, i.e. the separation of comb and sliding cutter or oscillating discs as soon as they are put to work at fast or extra fast speed.

According to a feature of the present invention I assemble the two blades in the cutting head and resting on a rear plate, a cover plate being provided over the blades and in order to maintain the correct pressure between the blades I provide a pressure plate either between the eover plate and the upper blade or between the rear plate and the lower blade, the said cover plate or the said rear plate having three or more adjustable projections adapated to press against the pressure plate so that it brings the correct pressure to bear on the blades. By this construction the pressure may be adjusted while the machine is working so that the correct pressure may be obtained.

According to this feature of the invention therefore I provide adjustable means operable to vary the degree of pressure between the two blades and under the control of the operator.

In order that the invention may be clearly understood and readily carried into effect reference is now directed to the accompanying drawings which illustrate in more detail an improved cutting or fiaying tool according to the invention and in which:

F GURE 1 is an elevation of the cutting tool with parts broken away;

FiGURE 2 is a detail view of a cover plate seen from the inside;

FIGURE 3 is a detail view of a pressure plate;

FIGURES 4 and 5 are detail views of a central mandrel for the rear plate with ball races incorporated;

FIGURE 6 is a detail view of another form of central mandrel with a surrounding liner;

FIGURE 7 is a section on the lines 6-6 of FIGURE 1;

FIGURE 7A is a section on line X-X of FIGURE 1;

FIGURE 73 is a central horizontal section through the handle projection, supporting plate, and mandrel;

FIGURE 8 is an elevation of a modified form of tool with parts broken away;

FIGURE 8A is a section taken on line Y-Y of FIGURE 8;

FIGURES 9 and 10 are detail views of the rear plate seen from the inside;

FIGURE 11 is a detail View of the driving part of one of the blades;

FIGURE 12 is a side view of FIGURE 11;

FIGURE 13 is a detail View of the driving part of the other blade;

FIGURE 14 is a side view of FIGURE 13;

FIGURES 15 and 16 are detail views of the cutting part of the blades partly broken away;

FIGURES 17 and 18 are a longitudinal section and an underneath view of one of the inserts drawn to an enlarged scale; and

FIGURE 19 illustrates a pressure plate.

Referring first to FIGURES 1 to 7B a rear or supporting plate 1 is clamped to a projection 1A from the main handle moulding 2 by a circular projecting mandrel 3 which is clamped to the projection by Allan screws 3A, the, plate and mandrel being centered by a pin 2A. The mandrel 3 may be small as shown in FIGURE 6 with a Phosphor bronze or like liner 4 surrounding the mandrel or it may be larger as shown in FIGURES 1 and 4. In FIGURES 4 and 5 the mandrel 3 is shown with two independent ball races 5 around the periphery to minimise friction and wear. The central mandrel 3 has tapped holes 6 which receive the Allan screws 3A whereby the mandrel may be secured to the rear plate 1 and holes 7 filled with felt or the like to absorb oil. The holes 7 have lateral passages 8, see FIGURE 6, to facilitate lubrication.

A lower blade 9 rests on the rear plate 1, fitting over the central mandrel and an upper blade 10 rests on the lower blade. The blades have a central opening to fit over the mandrel 3 and the interchangeable liner 4 may be provided so that if wear takes place the liner may be replaced and a new accurate bearing obtained. The blades 9 and 10 have teeth 11 around a part of the periphery so that as the blades are oscillated in opposite directions cutting is efiected.

The blades 9 and 10 are preferably driven by a compressed air operated motor housed within the handle moulding 2, a compressed air line, not shown being connected to a union 1'2, see FIGURE 1. The motor is operable to rotate an oval cam 13 which engages with an inserted plug member indicated at 14 at the bottom of each blade. The blades are therefore oscillated by the rotation of the cam as in my previous patent.

Disposed over the upper blade is a pressure plate 15 shaped as illustrated in FIGURE 3. The pressure plate has a central hole 16 to fit over the mandrel 3 so that the plate lies fiat on the upper blade 10. The pressure plate 15 is of about the same diameter as the rear or supporting plate 1 and may have a key to fit into a keyway slot in the mandrel to prevent the pressure plate from turning when the blades are in operation. The pressure plate 15 is circular except at the bottom where it is cut away at 17 and 18 to make room for the driving connections between the motor and the blades. The pressure plate 15 has three depressions 19 in its upper surface to receive adjustable projections in the form of small screws 20 provided on a cover plate 21. These depressions or cups 19 also act as keyways to prevent the pressure plate from rocking or following the movement of the blades.

The cover plate 21 is adapted to lie flat on the pressure plate 15 and has two countersunk holes each to receive a mounting screw 6A which passes through its hole and engages with holes 6' in the mandrel to hold the parts in position. The cover plate 21 also has three holes 21A to register with the depressions 19 in the pressure plate each hole being provided with an inserted, threaded nylon or like bush 22 and the small screws are inserted into the bushes to form the projections 29 which extend into the depressions 19 when the parts are assembled. In order toalter the working clearance of the blades 9 and lilbetween the two supporting plates or the pressure of one blade against the other the three small screws 20 may be adjusted by means of an Allan key to increase their inward projection which decreases the clearance or to decrease their inward projection which increases the clearance. Naturally when the clearance decreases the pressure increases and vice versa. The fact that the small screws 26 are mounted in nylon or like bushes 22 means that the screws 20 have a resilient mounting. This resilience is only slight but it is important in operation since it enables the screws 20 to absorb operational shocks. The nylon bushes 22 also minimise any tendency of the screws 20 to Work loose.

It will be understood that the number of the mounting screws 6 and 6 and the number of the small screws 20 and co-operating depressions 19 may be varied if desired. Also, in a modification not illustrated the pressure plate 15 may be provided between the rear plate 1 and the lower blade 9 and the small screws 20 for adjusting the pressure may be provided in the rear plate 1 instead of in the cover plate 21.

Referring now to FIGURES 8 to 19 we provide a construction of tool in which the disposition of the blades 9, 10 is matched with the direction of rotation of the cam 13. The cam 13 engages in the plug member 14, see particularly FIGURES 17 and 18, inserted in the lower end of each blade. is provided with a strengthened bush 23 let into the bottom of the blade and the cam engaging plug 14 is inserted into the bush. The bush 23 is welded or otherwise secured in position so as to be immovable relatively to the blade but the plug 14 is preferably movably In more detail each blade B It is also an advantage to be able to carry out the welding on the driving sections 26 without adversely affecting the cutting sections 25.

Therefore according to this embodiment of the invention the cutting tool comprises:

(1) A rear or supporting plate 1.

(2) A circular projecting mandrel 3 at the centre.

(3) A lower driving section 26 with upwardly projecting studs 27 and means to engage the cam.

(4) A lower cutting section 25 with two holes 27' to engage the studs 27 so that the lower driving section 26 and the lower cutting section 25 together form a composite lower blade 9. a

(5) An upper cutting section 25 with two holes 27'.

(6) An upper driving section 26 with downwardly projecting studs 27 to engage in the holes 27' of the upper cutting section 25 and having means to engage the oval cam so that the upper driving section 26 and the upper cutting section 25 together form a composite upper blade 10.

(7) A pressure plate 28 lying over the upper blade and central slot 29 therein to engage with an elongated projection 30 on the central boss to prevent rotation of the pressure plate.

(8) A top cover plate.

One feature of the present invention is therefore concerned with the provision of means for adjusting and maintaining any desired clearance or friction between one or more fiat cutters and their supporting plates. Another feature resides in matching the direction of rotation of the driving cam to the disposition of the blades and another feature resides in the construction of the blades in two parts.

FIGURES 17 and 18 illustrate a plug member in detail. It will be seen that there is a longitudinal passage 7 30' and a transverse passage 31 filled with felt or the mounted within the bush 23 so that it may oscillate therein as the blade moves in order that it may take up any required position relatively to the blade and to the oval cam 13 which projects into a slot 24 provided for the purpose in the plug 14.

In operation as one end of the cam 13 comes up through the blades 9 and 10 it tends to lift the blade with which that end of the cam 13 positively engages and as. the other end of the cam 13 goes down through the blades it tends to lower the blade with which that end'of the cam 13 positively engages. It will be understood that the cam 13 engages only with one end of each blade.

In order to overcomethis difficulty we so'arrange the cam 13 and the blades 9 and 10 that the cam 13 goes down through the bush 23 in the upper blade 10 and up through the bush 23 in the lower blade 9. In this way the upper blade 10 is urged downwardly and the lower blade 9 is urged upwardly and this tends to keep the two blades 9; 10 close to one another. In other words the rotation of the cam 13 tends to press the blades 9, 10' together.

As illustrated particularly in FIGURES 11, 13, 15 and 16 we make each of the blades in two parts a cutting section 25 and a driving section 26 these two parts being connected together in overlapping relation by studs 27 and holes 27'. One advantage of this construction is that the cutting sections 25 and the driving sections 26 may be made of different metal selected to suit the differing requirements of these differing parts.

like which carries oil and acts as a reservoir. In addi tion an insert 32 of nylon or the like is provided to prevent metal to metal contact between the top of the cam and the upper end of the slot 24.

I claim:

1. A cutting tool comprisinga cutting head, two blades ithe cutting head, a handle for the cutting head, means in the handle for oscillating the blades in oppositedirections, an extension of the handle having a mandrel on which the blades oscillate, a pressure plate mounted on the mandrel and disposed between the said extension and the adjacent blade in engagement with said blade, depressions in the exterior surface of said plate, and a screw engaging in each depression and mounted in the said extension, the screws comprising means for adjusting exteriorly of the extension the pressure on the said plate and the friction between the blades.

2. A cutting tool comprising a cutting head, two blades in the cutting head, a handle for the-cutting head, means in the handle for oscillating the blades in opposite directions, an extension of the handle, a mandrel fixed to the extension, a central opening in each blade, a removable and interchangeable liner freely mounted on the mandrel within the central opening of each blade, a pressure plate carried by the mandrel and disposed between the said extension and the adjacent blade, depressions in the exterior surface of the said plate, and a screw engaging each said depression and mounted in said extension, the screws comprising means for adjusting exteriorly of the extension the pressure on the said plate and the friction between the blades.

3. A cutting tool comprising a cutting head, two cutng blades in the head, a handle for the head, an extension of the handle having a cover plate which retains the blades in position, a rotatable oval cam in the handle, a bush fixed to each blade, a movable plug in each bush and in engagement with the cam to oscillate the'blades in opposite directions, the direction of rotation of the cam being such that the frictional engagement of the cam with the plugs tends to press the blades together, a pressure plate disposed between the said extension and the adjacent blade, and adjustable projections carried by the extension and engaging the said plate to vary the friction between the blades.

4. A cutting tool according to claim 3, wherein each plug has a transverse slot which is engaged by the cam and which has an insert of resilient material contacting the top of the cam, thereby preventing a metal to metal contact between the top of the cam and the plug.

References fitted in the file of this patent UNITED STATES PATENTS Klugel Aug. 15, 1899 Whitcomb Apr. 27, 1926 Williams Mar. 4, 1961 FOREIGN PATENTS Great Britain Jan. 25, 1897 

1. A CUTTING TOOL COMPRISING A CUTTING HEAD, TWO BLADES IN THE CUTTING HEAD, A HANDLE FOR THE CUTTING HEAD, MEANS IN THE HANDLE FOR OSCILLATING THE BLADES IN OPPOSITE DIRECTIONS, AN EXTENSION OF THE HANDLE HAVING A MANDREL ON WHICH THE BLADES OSCILLATE, A PRESSURE PLATE MOUNTED ON THE MANDREL AND DISPOSED BETWEEN THE SAID EXTENSION AND THE ADJACENT BLADE IN ENGAGEMENT WITH SAID BLADE, DEPRESSIONS IN THE EXTERIOR SURFACE OF SAID PLATE, AND A SCREW ENGAGING IN EACH DEPRESSION AND MOUNTED IN THE SAID EXTENSION, THE SCREWS COMPRISING MEANS FOR ADJUSTING EXTERIORLY OF THE EXTENSION THE PRESSURE ON THE SAID PLATE AND THE FRICTION BETWEEN THE BLADES. 